Mechanical seal having a seal insert mounted in a laminated shell

Abstract

A mechanical face seal including a non-rotable member fixed to a container and a rotatable member fixed to a shaft. The rotatable member includes a laminated holder constructed of press-fitted, metallic bands, and a non-metallic insert press-fitted in the holder. The outer band is in tension and the inner band in compression upon assembly of the holder so that the stresses in these parts tend to balance one another. Upon assembly of the insert to the holder, the inner band may be in tension.

What is claimed is: 
     
       1. A mechanical face seal comprising rotatable and non-rotatable members rubbingly engageable along substantially radial faces, one of said members including a holder formed by a plurality of bands which are press fitted to one another, the outermost band being in tension and the innermost band in compression so that the stresses in the bands tend to balance one another, and an annular insert press-fitted into the holder and formed with one of said rubbingly engageable faces. 
     
     
       2. A mechanical face seal as claimed in claim 1, said bands being constructed of metal and said insert being constructed of a low-friction, non-metallic material. 
     
     
       3. A mechanical face seal as claimed in claim 2, said holder including two concentric bands, said innermost band being in tension upon initial insertion of said insert into said holder. 
     
     
       4. In a mechanical face seal of the type including a rotatable seal member fixed to a shaft and a non-rotatable member, said rotatable and non-rotatable members having confronting radial faces in rubbing engagement; the improvement wherein one of said members comprises a composite assembly including at least two concentric metallic bands press-fitted together and forming a laminated holder, the outermost band being in tension and innermost band being in compression so that stresses in the bands tend to balance one another, and a non-metallic insert press fitted in the holder. 
     
     
       5. The improvement as claimed in claim 4, said holder including two concentric bands, said innermost band being in tension upon initial insertion of said insert into said holder.